Sarcopenia

Sarcopenia

Sarcopenia is the degenerative loss of skeletal muscle mass often associated with aging which gradually weakens a person and causes increasing difficulty in walking and moving around. There are currently very few treatment options for this debilitating condition.

There are factors that enhance the formation of muscle and factors that inhibit muscle formation and Myostatin is one of the main factors that inhibit muscle growth, but there are related proteins with similar functions. Myostatin and related proteins bind to receptors on the muscle cells. The binding is a signal for the muscle fiber to stop growing . When the gene for the myostatin protein is mutated and no myostatin is made, this leads to increased muscle formation in animals (Belgian blue cows, Texel sheep and greyhounds) and humans.

Thus, if it is possible to prevent myostatin from doing its job, this should enhance muscle formation. This could compensate for the loss of muscle tissue in sarcopenia, Muscular Dystrophy and other muscule wastaging conditions and can be achieved by gene therapy for myostatin inhibition. These antibodies bind to myostatin and prevent it from reaching the gene switches and turning down the level of expression thus mitigating the loss of muscle.

In tests this gene has been delivered to mice and monkeys using an AAV viral vector and the injections resulted in an increase in muscle mass and muscle strength.

This early work prompted further study and promising results have been demonstrated in a recent gene therapy for Beckers muscular dystrophy at the Nationwide children’s hospital. There were some positive results in most patients.The results of this clinical trial were so promising they have been expanded to treat the related condition duchenne muscular dystrophy, again as part of clinical trials at the Nationwide children’s hospital. You can learn more about the DMD clinical trial here.

These promising studies and a number of others have encouraged us to develop a gene therapy to treat muscle wastage. It is likely such a therapy would be of benefit in a variety of muscular conditions.